724-746-5500
blackbox.com
2 of 3
FEATURES
• Tests network cable pairs for Power
over Ethernet (PoE).
• Identifies the power type as IEEE
802.3af, Cisco Inline Power (ILP),
or nonstandard.
• Makes power measurements with
loads simulating powered devices.
• Displays voltage, polarity, and power
configuration for wire pairs.
• Measures loop resistance to identify
damaged cables and bad punchdowns.
• Detects 10/100/1000BASE-TX link
speed and duplex mode.
• Measures cable length, opens,
and shorts.
• Provides a port ID function.
OVERVIEW
Use NetPower to conduct power tests with simulated
loads to ensure that VoIP phones, access points, security
cameras, and other equipment will operate properly on
your PoE network.
The power is in your hands.
If you’re responsible for installing and maintaining
networks that use Power over Ethernet (PoE), make the
NetPower an essential part of your toolbox.
This advanced, easy-to-use handheld tester can give you
the peace of mind you need to check and verify Power over
Ethernet links—before you accidentally damage any
equipment! You can even differentiate between IEEE standard
power and manufacturer-specific power. In addition, power
for devices can run over different pairs or on all pairs, and
the NetPower will tell you in no time.
Other test functions include tone generation for cable
tracing. You can also use the tester to measure cable length
and identify switch or hub ports.
2/15/2007
#26542
What is PoE?
The seemingly universal network connection, twisted-pair
Ethernet cable, has another role to play: providing electrical
power to low-wattage electrical devices. Power over Ethernet
(PoE) was ratified by the Institute of Electrical and Electronic
Engineers (IEEE) in June 2000 as the 802.3af-2003 standard.
It defines the specifications for low-level power delivery —
roughly 13 watts at 48 VDC— over twisted-pair Ethernet cable
to PoE-enabled devices such as IP telephones, wireless access
points, Web cameras, and audio speakers.
How does PoE work?
The way it works is simple. Ethernet cable that meets
CAT5 (or better) standards consists of four twisted pairs of
cable, and PoE sends power over these pairs to PoE-enabled
devices. In one method, two wire pairs are used to transmit
data, and the remaining two pairs are used for power. In the
other method, power and data are sent over the same pair.
When the same pair is used for both power and data,
the power and data transmissions don’t interfere with each
other. Because electricity and data function at opposite ends
of the frequency spectrum, they can travel over the same
cable. Electricity has a low frequency of 60 Hz or less,
and data transmissions have frequencies that can range
from 10 million to 100 million Hz.
Basic structure.
There are two types of devices involved in PoE
configurations: Power Sourcing Equipment (PSE) and
Powered Devices (PD).
Technically Speaking
PSEs, which include end-span and mid-span devices,
provide power to PDs over the Ethernet cable. An end-span
device is often a PoE-enabled network switch that’s designed
to supply power directly to the cable from each port. A mid-
span device is inserted between a non-PoE device and the
network, and it supplies power from that juncture.
Power injectors, a third type of PSE, supply power to
a specific point on the network while the other network
segments remain without power.
PDs are pieces of equipment like surveillance cameras,
sensors, wireless access points, and any other devices that
operate on PoE.
PoE applications and benefits.
• Use one set of twisted-pair wires for both data and low-
wattage appliances.
• In addition to the applications noted previously, PoE also
works well for video surveillance, building management,
retail video kiosks, smart signs, vending machines, and
retail point-of-information systems.
• Save money by eliminating the need to run electrical wiring.
• Easily move an appliance with minimal disruption.
• If your LAN is protected from power failure by a UPS,
the PoE devices connected to your LAN are also protected
from power failure.
